This invention relates to a device for stringing an electrical conductor on an insulator above the ground for aerial power distribution or transmission.
The conductors to be strung may be either insulated cables or conductors of the bare wire type.
There has been a long-felt need for such a stringing device which is economical to manufacture and to use and which may be used with an insulator which will accept the device and permit a conductor to be installed and tensioned on a plurality of insulators without the use of the customary stringing roller blocks or a temporary stringing pin insulator and the usual temporary support of the conductor while the stringing device is removed and a permanent insulator is installed.
There has also been a long-felt need for such a stringing device which is not subjected to excessive wear when the conductor is pulled through it during the stringing operation and which can be used repeatedly from job to job.
U.S. Pat. No. 3,739,075 dated June 12, 1973, owned by Hendrix Wire & Cable Corporation, the assignee of the present application, discloses one unsuccessful attempt to meet said long-felt needs. In the insulator of that patent, the body of the insulator was provided with a cylindrical eye 15 having a circular passage 16 through which the conductor cable was pulled during the stringing step. Because the diameter of the passage 16 was much greater than the diameter of the conductor, it was necessary to use wire means 38, wire means 43 or elastic tie means 45 to hold the conductor in the passage 16. Installation of such means was very time consuming. In addition, the cylindrical eye 15 was not made of a sufficiently wear-resistant plastic to prevent excessive wear when the conductor was pulled through it during stringing.
Reliable Electric Company's, Synthetic Products Company Division, attempted to meet the long-felt need with a temporary stringing pin insulator which accommodates conductors up to 17/8" in diameter. This stringing pin insulator is shown in U.S. Pat. No. Des. 235,190. As an accessory, a channel shaped replacable insert is available to limit wear of the temporary insulator but it is not cylindrical and cannot be rotated to distribute wear from job to job.
To the best of our knowledge, the above described prior art is the closest prior art to the stringing device of the present invention.